JPH08136881A - Liquid crystal projector - Google Patents

Abstract

PURPOSE: To effectively utilize the energy of the light in the visible region being conventionally useless among rays of light of a light source. CONSTITUTION: Liquid crystal display elements 3, a picture signal circuit 4, a light source 5, a cold mirror and reflector 6, a projecting lens 7, a power source circuit 8, a cooling fan 9, etc., are included in a liquid crystal projector 1. The cold mirror and reflector 6 makes the light in the visible region La included in rays of light of the light source 5 reflect to the liquid crystal elements 3 and makes the light in the invisible region Lb included in the rays relieve by making it transmit through the reflector to separate it from the light in the visible region La. In this projector, solar batteries 10 are especially provided to convert the light in the invisible region Lb into electric power, which is supplied to the picture signal circuit 4. It is desirable to provide a concave mirror 11 so as to increase the light in the invisible regoin Lb to be made incident on solar batteries 10. The concave mirror 11 has holes making the light in the visible region La transmit and makes the light in the invisible region Lb reflect to the solar batteries 10 with its parabolic surface (or its elliptic surface).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal projector, and more particularly to the effective use of invisible light contained in the light of a light source and wasted conventionally.

[0002]

2. Description of the Related Art A conventional liquid crystal projector 1 will be described with reference to FIG. Reference numeral 3 is a liquid crystal display element, 4 is an image signal circuit for driving the liquid crystal display element 3, 5 is a light source (lamp) arranged on the back side of the liquid crystal display element 3, and 6 is light from the light source 5. Is a cold mirror reflector for reflecting visible light La contained in the back surface of the liquid crystal display element 3 and transmitting non-visible light Lb contained in the light to escape and separating the visible light La from the visible light La, and 7 is a liquid crystal display element 3 A projection lens 8 arranged on the front side for magnifying and projecting the transmitted light Lc of the element 3 onto the screen,
Is a power supply circuit, 9 is a cooling fan, and these main parts are housed in the housing 2.

[0003]

In the conventional liquid crystal projector 1, the invisible light Lb separated by the cold mirror / reflector 6 is not particularly used and is released to the inside of the housing 2 to increase the temperature. It was one of the causes. Moreover, in order to suppress this temperature rise, a large fan 9 with large power consumption was required.

The present invention has been made in view of the above circumstances, and an object thereof is to effectively utilize the energy of the invisible light Lb which is contained in the light of the light source and has conventionally been wasted. .

[0005]

[Means for Solving the Problems]

(1) According to the first aspect of the invention, the invisible light Lb separated by the cold mirror deflector is received and converted into electric power,
A solar cell that supplies the power to the image signal circuit 4 is provided. (2) In the invention of claim 2, in the above (1), a reflecting mirror which is disposed on the back side of the liquid crystal display element 3 and reflects the invisible light Lb separated by the cold mirror reflector 6 to the solar cell. It is provided.

(3) In the invention of claim 3, in the above (2), the reflecting mirror is composed of a concave mirror arranged with the center line Lo of the light source 5 at the axis, and a cold mirror, A through hole for transmitting the visible light La reflected by the reflector 6 is formed.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention is shown in FIG. 1 by giving the same reference numerals to the portions corresponding to those in FIG. In the present invention, the solar cell 10 is provided, the invisible light Lb separated by the cold mirror / reflector 6 is received and converted into electric power, and the electric power is supplied to the image signal circuit 4.

The solar cell 10 is 10a to 10e in this example.
Since the respective generated voltages are low, they are connected in series as shown in FIG. 3 to have a required size. FIG.
In the example of B, the concave mirror 11 which is a kind of reflecting mirror is arranged on the back side of the liquid crystal display element 3. The concave mirror 11 is arranged with the center line Lo of the light source 5 at the axis, and its reflecting surface is a parabolic surface or an elliptical surface, and the visible light La reflected by the cold mirror reflector 6 is directly transmitted to the center thereof. A through hole 11a is provided. A part of the invisible light Lb separated by the cold mirror / reflector 6 is reflected by the concave mirror 11 and is incident on the solar cell 10. Therefore, it is possible to obtain larger power than in the case of FIG. 1A.

[0009]

【The invention's effect】

(1) Since a considerable amount of the invisible light Lb separated by the cold mirror reflector 6 is converted into electric energy, the capacity of the power supply circuit 8 can be reduced. (2) The amount of non-visible light Lb converted into heat is small,
Since the temperature rise in the housing is suppressed, the cooling fan 9 can be downsized. (3) By reducing the capacity of the power supply circuit 8 and downsizing the cooling fan, the power consumption of the liquid crystal projector can be considerably reduced as compared with the conventional one.

[Brief description of drawings]

FIG. 1 is a principle configuration diagram showing an embodiment of the present invention.

FIG. 2 is a perspective view showing an arrangement of solar cells 10 in FIG.

FIG. 3 is a connection diagram of the solar cell 10 and the image signal circuit 4 of FIG.

FIG. 4 is a perspective view of the concave mirror 11 of FIG. 1B.

FIG. 5 is a principle configuration diagram of a conventional liquid crystal projector.

Claims (3)

[Claims] 1. A transmissive liquid crystal display device, an image signal circuit for driving the liquid crystal display device, a light source arranged on the back side of the liquid crystal display device, and light from the light source is condensed to obtain the light. A visible light contained in the liquid crystal display element is reflected on the back surface of the liquid crystal display element, and a non-visible light contained in the light is transmitted to separate the visible light from a cold mirror reflector; A projection lens for enlarging and projecting the transmitted light of the element onto a screen; and a liquid crystal projector comprising: receiving invisible light separated by the cold mirror reflector and converting it into electric power, and converting the electric power into the image. A liquid crystal projector comprising a solar cell for supplying a signal circuit. 2. The reflecting mirror according to claim 1, further comprising a reflecting mirror disposed on the back side of the liquid crystal display device, the reflecting mirror reflecting invisible light separated by the cold mirror reflector to the solar cell. LCD projector. 3. The concave mirror according to claim 2, wherein the reflecting mirror is a concave mirror arranged with a center line of the light source as an axis.
A liquid crystal projector having a through hole formed in the center thereof for transmitting the visible light reflected by the cold mirror reflector.